@PetrolIf you mean to compile with general compiler's optimisation like -O3, and via new gcc 8.2.0 : then that can probably give a very little speed up, but that for all platforms, not only for x1000. But if you mean -D_ARCH_PWR4 then nope, as that is program specific flag, which done for euae jit parts only. In odyssey we even didn't use jit, as it x86 only, and even if, still all should be done for any realisation of jit differently.